The present invention relates to a shield tunneling machine and more particularly a shield tunneling machine which can suitably control the posture of a segment, whereby the segments can be easily and quickly assembled.
Segments are erected into a cut-off and reinforcing wall over the inner surface of a tunnel driven by a tunneling machine. In other words, in order to facilitate the erection of a ring of wall in a narrow tunnel, the ring is composed of a plurality of segments and such arcuate segments are assembled one by one. In general the shield tunneling machines are provided with a device (erector arm) for erecting the segments each weighing more than one ton. Such segment assembling device comprises, as shown in FIG. 1, a circular revolving ring b mounted within a shield frame a such that the circular revolving ring b can freely rotate along the inner surface of the shield frame a, a lifting beam c mounted on the circular revolving ring b such that the lifing beam c can move in the radial direction and a segment holding mechanism d mounted on the lifting beam c. In general the segment holding mechanism d is axially movable.
Therefore, the shield tunneling machine can move a segment which is held by the segment holding mechanism d to a desired place of the inner surface wall of a tunnel by the cooperation of the circular revolving ring b and the lifting beam c.
The conventional shield tunneling machine can move a segment in the circumferential, radial and axial directions of the shield frame a, but cannot adjust the posture of the segment and/or to assemble the segment with the partially assembled ring of segments. Therefore, if the segment which has been moved to the partially assembled ring is inclined at an angle relative to the partially assembled ring, a few workers must manually make a fine adjustment. As a result, the erection of a segment is very troublesome. Furthermore, the assembled segments are manually linked by bolts. As a result, the erection of segments become further troublesome. Furthermore, since the handling and assembly of heavy segments is made in a narrow tunnel, it requires many workers and is dangerous. As a consequence, the tunnel construction costs are considerably increased.
The present invention was made to overcome the above and other problems encountered in the conventional shield tunneling machines and has for its object to provide a shield tunneling machine which can suitably control the posture of a segment and can automatically link a segment to the partially assembled ring of segments, whereby the erection and assembly of segments can be accomplished easily and quickly and the tunnel construction costs can be reduced.
The effects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments thereof taken in conjunction with the accompanying drawings.